Sea anemones are venomous marine animals belonging to the phylum Cnidaria, class Anthozoa. Sea anemone venoms are a complex mixture of bioactive compounds, including disulfide-rich peptides [1,2]. Numerous such peptides have found applications as research tools, and others are of interest as therapeutic leads. Our recent transcriptomic and proteomic studies of the Australian sea anemone Telmatactis australiensis identified a transcript for a peptide designated U-IPTX-Tsp3. U-IPTX-Tsp3 is a 38-residue peptide containing 3 disulfide bonds. U-IPTX-Tsp3 has sequence similarity to some peptide toxins known to interact with a range of ion channels (NaV, N-methyl-D-aspartate (NMDA)-subtype of ionotropic glutamate receptor (GRIN) and CaV). U-IPTX-Tsp3 was produced by periplasmic expression in Escherichia coli as it enables the production of both unlabeled and isotopically labelled peptides for functional and structural studies, respectively. The LC-MS profile showed a pure peak whose molecular mass was 6 Da less than that of the reduced form of the peptide, indicating the successful formation of 3 disulfide bonds. The 1D 1H NMR spectrum of U-IPTX-Tsp3 at pH 5 and 25°C showed that the peaks in the amide region were well dispersed indicating that the peptide adopts a well-defined tertiary structure. The solution structure of U-IPTX-Tsp3 will be determined using NMR spectroscopy, and the peptide will be tested in various functional assays, including electrophysiological, cytotoxicity and hemolytic assays.